Iceland was extensively forested when it was first settled. When the Vikings first arrived in the 9th century, the Nordic island was covered in 25 to 40 percent forest, compared to 1% in the present day. In the late 12th century, Ari the Wise (Ari Thorgilsson, 1067–1148 AD), Iceland’s most prominent medieval chronicler, described it in the Íslendingabók (Book of Icelanders^{Notes 1}) as “forested from mountain to sea shore”. Unfortunately, after the permanent human settlement, the forests were heavily exploited for firewood, timber and to make room for farming. Within a few centuries, almost all of Iceland’s trees were gone. This rapid deforestation has resulted in massive soil erosion that puts the island at risk for desertification. Today, many farms have been abandoned. Three-quarters of Iceland’s 100,000 km²is affected by soil erosion, 18,000 km² (6,900 sq mi) serious enough to make the land useless. But,, with the help of forestry societies and forest farmers, Iceland’s trees are slowly beginning to make a comeback.